Roughly defined as any property other than pitch, duration, and loudness that allows two sounds to be distinguished, timbre is a foundational aspect of hearing. The remarkable ability of humans to recognize sound sources and events (e.g., glass breaking, a friend's voice, a tone from a piano) stems primarily from a capacity to perceive and process differences in the timbre of sounds. Timbre raises many important issues in psychology and the cognitive sciences, musical acoustics, speech processing, medical engineering, and artificial intelligence. Current research on timbre perception unfolds along three main fronts: On the one hand, researchers explore the principal perceptual processes that orchestrate timbre processing, such as the structure of its perceptual representation, sound categorization and recognition, memory for timbre, and its ability to elicit rich semantic associations, as well as the underlying neural mechanisms. On the other hand, timbre is studied as part of specific scenarios, including the perception of the human voice, as a structuring force in music, as perceived with cochlear implants, and through its role in affecting sound quality and sound design. Finally, computational acoustic models are sought through prediction of psychophysical data, physiologically inspired representations, and audio analysis-synthesis techniques. Along these three scientific fronts, significant breakthroughs have been achieved during the last decade. This volume will be the first book dedicated to a comprehensive and authoritative presentation of timbre perception and cognition research and the acoustic modeling of timbre. The volume will serve as a natural complement to the SHAR volumes on the basic auditory parameters of Pitch edited by Plack, Oxenham, Popper, and Fay, and Loudness by Florentine, Popper, and Fay. Moreover, through the integration of complementary scientific methods ranging from signal processing to brain imaging, the book has the potential to leverage new interdisciplinary synergies in hearing science. For these reasons, the volume will be exceptionally valuable to various subfields of hearing science, including cognitive auditory neuroscience, psychoacoustics, music perception and cognition, but may even exert significant influence on fields such as musical acoustics, music information retrieval, and acoustic signal processing. It is expected that the volume will have broad appeal to psychologists, neuroscientists, and acousticians involved in research on auditory perception and cognition. Specifically, this book will have a strong impact on hearing researchers with interest in timbre and will serve as the key publication and up-to-date reference on timbre for graduate students, postdoctoral researchers, as well as established scholars.

Contents:
Chapter One. A Little History. 1.1 Introduction. 1.2 Early history. 1.3 Later history 1.4 The future. Chapter Two: Foundations of Active Control. 2.1 Physical mechanisms 2.2 Basic structure of active noise Control systems. 2.3. Control system optimisation. 2.3.1 Influence of control source output power and placement. 2.3.2 Influence of error sensor placement. 2.3.3 Influence of reference signal delay and quality. Chapter Three: The Electronic Control System. 3.1 Introduction 3.2 Control Filter. 3.3 Cancellation path transfer function estimation. 3.4 Adaptation algorithms. 3.4.1 FXLMS algorithm for adapting the weights of an FIR filter. 3.4.2 Multi-channel and filtered-U RLS algorithms for IIR filters. 3.4.3 Genetic algorithms. 3.4.3.1 Killing selection instead of survivor selection. 3.4.3.2 Weight String Instead of Binary Encoding. 3.4.3.3 Mutation probability and amplitude 3.4.3.4 Rank-based selection 3.4.3.5 Uniform crossover 3.4.3.6 Genetic algorithm parameter adjustment 3.4.3.7 Performance measurement 3.5 Putting it all together 3.6 Important practical controller implementation issues 3.6.1 Microprocessor selection. 3.6.2 Converter type and group delay considerations 3.6.3 Digital sampling rate 3.6.4 Algorithm considerations 3.6.5 Accuracy of controller output. Chapter Four: Active Noise Control Sources. 4.1 Acoustic sources. 4.2 Vibration sources. Chapter Five: Error Sensors. 5.1 Microphones. 5.2 Vibration sensing and control of sound radiation 5.3 Sound intensity and energy density control. 5.4 Control algorithms for various sensing strategies. 5.4.1 Shaped or distributed structural sensors. 5.4.2. Sound intensity 5.4.3 Energy density. 5.4.4 Power or intensity squared. Chapter Six: Applications of Active Noise Control. 6.1 Some general considerations. 6.2 Application Examples. 6.2.1 Sound propagation in ducts. 6.2.2.1 Plane wave propagation 6.2.2.2 Higher order mode propagation 6.2.3 Sound radiation from vibrating structures 6.2.3.1 Physical control mechanisms 6.2.3.2 Control actuators and error sensors. 6.2.4 Active headsets and ear muffs. 6.2.4.1 Feedback systems 6.2.4.2 Feedforward systems 6.2.4.2 Transducer considerations 6.2.4.3 Transducer considerations 6.2.5 Sound transmission into enclosed spaces 6.2.5.1 Global reduction of low frequency tonal noise in propellor aircraft 6.2.5.2 Reduction of interior noise in diesel engine-driven, mobile mining equipment 6.2.5.3 Local reduction of broadband noise in large aircraft 6.2.5.4 Global reduction of low frequency road noise in cars 6.2.6 Active vibration isolation. 6.3 Examples of applications which are impractical. 6.3.1 Global reduction of broadband or high frequency tonal noise in large aircraft 6.3.2 Global reduction of broadband or transient noise transmitted into a building space. 6.3.3 Reduction of traffic or aircraft flyover noise transmitted into a building. 6.3.4 Global reduction of tonal or periodic noise in a large space such as a factory which contains many noise sources. 6.3.5 Global reduction of broadband in a large factory 6.3.6 Reduction of broadband noise outdoors 6.3.7 Reduction of transient noise outdoors. Chapter Seven: Current and Future Directions. 7.1 Commercial control system requirements 7.1.1 Controller hardware 7.1.2 Controller software 7.2 Acoustic system software 7.3 Current research directions 7.3.1 Sound sources 7.3.2 Error sensors 7.3.3 Optimisation of control source and error sensor locations 7.3.4 Control filters and algorithms 7.3.5 Coupled systems 7.3.6 Hybrid active/passive silencers. 7.4 Summary. References. Useful web-sites for more information.

Current standard numerical methods are of little use in solving mathematical problems involving boundary layers. In Robust Computational Techniques for Boundary Layers, the authors construct numerical methods for solving problems involving differential equations that have non-smooth solutions with singularities related to boundary layers. They present a new numerical technique that provides precise results in the boundary layer regions for the problems discussed in the book. They show that this technique can be adapted in a natural way to a real flow problem, and that it can be used to construct benchmark solutions for comparison with solutions found using other numerical techniques.

Focusing on robustness, simplicity, and wide applicability rather than on optimality, Robust Computational Techniques for Boundary Layers provides readers with an understanding of the underlying principles and the essential components needed for the construction of numerical methods for boundary layer problems. It explains the fundamental ideas through physical insight, model problems, and computational experiments and gives details of the linear solvers used in the computations so that readers can implement the methods and reproduce the numerical results.

This volume is based on lectures delivered at the 2020 AMS Short Course ""Mean Field Games: Agent Based Models to Nash Equilibria,"" held January 13-14, 2020, in Denver, Colorado. Mean field game theory offers a robust methodology for studying large systems of interacting rational agents. It has been extraordinarily successful and has continued to develop since its inception. The six chapters that make up this volume provide an overview of the subject, from the foundations of the theory to applications in economics and finance, including computational aspects. The reader will find a pedagogical introduction to the main ingredients, from the forward-backward mean field game system to the master equation. Also included are two detailed chapters on the connection between finite games and mean field games, with a pedestrian description of the different methods available to solve the convergence problem. The volume concludes with two contributions on applications of mean field games and on existing numerical methods, with an opening to machine learning techniques.

Presenting a comprehensive description of the theory and physics of high-intensity ultrasound, this book also deals with a wide range of problems associated with the industrial applications of ultrasound, mainly in the areas of metallurgy and mineral processing.
The book is divided into three sections, and Part I introduces the reader to the theory and physics of high-intensity ultrasound. Part II considers the design of ultrasonic generators, mechanoacoustic radiators and other vibrational systems, as well as the control of acoustic parameters when vibrations are passed into a processed medium. Finally, Part III describes problems associated with various uses of high-intensity ultrasound in metallurgy. The applications of high-intensity ultrasound for metal shaping, thermal and thermochemical treatment, welding, cutting, refining, and surface hardening are also discussed here.
This comprehensive monograph will provide an invaluable source of information, which has been largely unavailable in the West until now.

This book explores recent developments in QIA and describes the application of the theory to different branches of wave physics, from plasma physics, quantum physics, and ionospheric radio wave propagation to acoustics, optics, and astrophysics.
This is an up-to-the-minute exposition of the latest developments in an important new area, written by authors of outstanding reputation. A rich source of both theoretical methods and practical applications, it covers a wide range of problems of general physical significance.
Until recently, there was no effective method for describing waves in weakly anisotropic inhomogeneous media. The method of quasi-isotropic approximation (QIA) of geometrical optics was developed to overcome this problem. The QIA approach bridges the gap between geometrical optics of isotropic media (Rytov method) and that of anisotropic media (Courant-Lax approach), thus providing a complete picture of the geometrical optics of inhomogeneous media.

Quantum Chemistry provides a coherent and structured approach in introducing the concept of 'quantum' to the students of quantum mechanics. An attempt is made to bring out the subtleties of quantum mechanics, hidden in its abstract laws and equations, applicable to the atomic domain by showing its relevance to the observable macroscopic world as well. The book will help students dispel the stigma associated with quantum mechanics. The emphasis on conceptual approach provides a platform to stand on, and a stimulus to pursue higher quantum mechanics-the doorway to the all-pervasive quantum world. Print edition not for sale in South Asia (India, Sri Lanka, Nepal, Bangladesh, Pakistan or Bhutan).

This book presents topics in a single source format using unified spectral theory of computing. With developments of DNS and LES, practitioners are rediscovering waves as important in fluid flows, and capturing these numerically is central to high accuracy computing. Analysis of waves and its use in numerical methods in propagating energy at the right velocity (dispersion effects) and with right amplitude (dissipation) are essential. Most industrial codes using Reynolds-averaged Navier-Stokes equations with turbulence models cannot conceive of capturing waves. The new themes covered in this book are: * Correct error propagation analysis * Practical compact schemes and global analysis tool * Aliasing error and its alleviation * Spurious upstream propagating q-waves * Explanation of the Gibbs phenomenon * New 1D and 2D filters for LES/DNS without SGS modelling * Anisotropic skewed wave propagation * Development and analysis of dispersion relation preservation (DRP) schemes * Flow instabilities and wave propagation phenomena

Dynamics of Water Surface Flows and Waves provides theoretical descriptions of the whole life of water surface waves through their birth, propagation, evolution and finally breaking. While initial capillary waves are created via instability at air-water interfaces, potential wave theories adequately describe interactions of waves with current, bathymetry and structure. In the final breaking stage, potential fluid motions in the waves rapidly evolve into vortical turbulent flows that disturb the surfaces, resulting in entrainment of air-bubbles and ejection of sea spray in bursting bubbles floating on the surface. All theories and analytical methods required to understand the series of wave processes, over diverse areas of subjects, including turbulence, diffusion, vortex and capillary dynamics, shallow water approach, and stability analysis, as well as the conventional potential wave theory, are comprehensively covered in this book. All of the mathematical formulas are consistently developed from theorems and linked with physics, which provides theoretical understanding and further interest in wave dynamics. This is an ideal graduate-level textbook or reference for engineers and researchers in the fields of fluid and wave mechanics, coastal and ocean engineering.

This volume comprises over 50 contributions resulting from the Ocean Reverberation Symposium, held 25-29 May 1992 in La Spezia, Italy. The contributions are presented in eight sections: Scattering Mechanisms, High Frequency Measurements and Mechanisms, Reverberation Modelling, ARSRP Mid-Atlantic Ridge Experiment, Low Frequency Measurements, Volume Scattering, Signal Processing Issues and Applications. The work addresses the emerging trends in ocean reverberation research. The availability of high-power, low-frequency sources and highly directional arrays has brought with it the tools, and the need, to study long-range reverberation. The use of projector sources and various waveforms, rather than explosives, allows the use of signal processing techniques to enhance the extraction of information about the reverberation and scattering processes.

This volume contains a selection of full-length papers on connections between curve and surface methods - in such areas as computer vision, data fitting, image processing and computer-aided geometric design - and the theory and applications of wavelet analysis. These papers were delivered at the Second International Conference on Curves and Surfaces in Chamonix, France, in June 1993. This is the first of two volumes of papers from this conference.

Suitable for both individual and group learning, Engineering Acoustics focuses on basic concepts and methods to make our environments quieter, both in buildings and in the open air.

The author s tutorial style derives from the conviction that understanding is enhanced when the necessity behind the particular teaching approach is made clear. He also combines mathematical derivations and formulas with extensive explanations and examples to deepen comprehension.

Fundamental chapters on the physics and perception of sound precede those on noise reduction (elastic isolation) methods. The last chapter deals with microphones and loudspeakers.

Moeser includes major discoveries by Lothar Cremer, including the optimum impedance for mufflers and the coincidence effect behind structural acoustic transmission.

The appendix gives a short introduction on the use of complex amplitudes in acoustics.

"

This volume represents the findings of the first test cases considered by ERCOFTAC (European Research Consortium on Flow Turbulence and Combustion). The workshop, held in Lausanne, Switzerland, in 1990, studied five test cases: boundary layer in an S-shaped duct; periodic array of cylinders; transition in a boundary layer under the influence of free-stream turbulence; axisymmetric confined jet flows. These test cases represented the interests of both the academic and industrial groups in finding out the limits of various models and codes to predict real problems supported by experimental data. The articles summarise the work of each group and point to refinements and further study to perfect the models. As such there will be much of interest to all professionals and researchers concerned with the prediction of flows and turbulence.

This advanced monograph is concerned with modern treatments of central problems in harmonic analysis. The main theme of the book is the interplay between ideas used to study the propagation of singularities for the wave equation and their counterparts in classical analysis. In particular, the author uses microlocal analysis to study problems involving maximal functions and Riesz means using the so-called half-wave operator. To keep the treatment self-contained, the author begins with a rapid review of Fourier analysis and also develops the necessary tools from microlocal analysis. This second edition includes two new chapters. The first presents Hoermander's propagation of singularities theorem and uses this to prove the Duistermaat-Guillemin theorem. The second concerns newer results related to the Kakeya conjecture, including the maximal Kakeya estimates obtained by Bourgain and Wolff.

Broadband communications is widely recognized as one of the most revolutionary emerging technologies of the last decade of the 20th century. This book provides a comprehensive snapshot of leading-edge research across a structured set of topics vital to broadband communications infrastructure for the information age.

This volume contains an overview of the state of turbulence research with some bias towards work done in Europe. It represents an almost complete collection of the invited and contributed papers delivered at the Seventh European Turbulence Conference, sponsored by EUROMECH and ERCOFTAC and organized by the Observatoire de la Cote d'Azur. High-Reynolds number experiments combined with techniques of imaging, non-intrusive probing, processing and simulation provide high-quality data which put significant constraints on possible theories. For the first time, it has been shown, for a class of passive scalar problems, why dimensional analysis sometimes gives the wrong answers and how anomalous intermittency corrections can be calculated from first principles. The volume is thus geared towards specialists in the area of flow turbulence who could not attend the conference as well as anybody interested in this rapidly-moving field.

foundations of duct acoustics to the acoustic design of duct systems, through practical modeling, optimization and measurement techniques. Discover in-depth analyses of one- and three-dimensional models of sound generation, propagation and radiation, as techniques for assembling acoustic models of duct systems from simpler components are described. Identify the weaknesses of mathematical models in use and improve them by measurement when needed. Cope with challenges in acoustic design, and improve understanding of the underlying physics, by using the tools described. An essential reference for engineers and researchers who work on the acoustics of fluid machinery ductworks.

This book provides a concise introduction to continuum mechanics, with a particular emphasis on fluid dynamics, suitable for upper undergraduate students in applied mathematics and related subjects. Starting with a preliminary chapter on tensors, the main topic of the book begins in earnest with the chapters on continuum kinematics and dynamics. Following chapters cover linear elasticity and both incompressible and compressible fluids. Special topics of note include nonlinear acoustics and the theory of motion of viscous thermal conducting compressible fluids. Based on an undergraduate course taught for over a decade, this textbook assumes only familiarity with multivariate calculus and linear algebra. It includes many exercises with solutions and can serve as textbook for lecture courses at the undergraduate and masters level.

This book is a collection of papers presented at Acoustics and Vibration of Mechanical Structures 2017 - AVMS 2017 - highlighting the current trends and state-of-the-art developments in the field. It covers a broad range of topics, such as noise and vibration control, noise and vibration generation and propagation, the effects of noise and vibration, condition monitoring and vibration testing, modeling, prediction and simulation of noise and vibration, environmental and occupational noise and vibration, noise and vibration attenuators, as well as biomechanics and bioacoustics. The book also presents analytical, numerical and experimental techniques for evaluating linear and non-linear noise and vibration problems (including strong nonlinearity). It is primarily intended for academics, researchers and professionals, as well as PhD students in various fields of the acoustics and vibration of mechanical structures.

How do we understand culture and shape its future? How do we cross the bridge between culture as ideas and feelings and physical, cultural objects, all this within the endless variety and complexity of modern and traditional societies? This book proposes a Physical Culture Theory, taking culture as a self-organizing impulse pattern of electric forces. Bridging the gap to consciousness, the Physical Culture Theory proposes that consciousness content, what we think, hear, feel, or see is also just this: spatio-temporal electric fields. Music is a perfect candidate to elaborate on such a Physical Culture Theory. Music is all three, musical instrument acoustics, music psychology, and music ethnology. They emerge into living musical systems like all life is self-organization. Therefore the Physical Culture Theory knows no split between nature and nurture, hard and soft sciences, brains and musical instruments. It formulates mathematically complex systems as Physical Models rather than Artificial Intelligence. It includes ethical rules for maintaining life and finds culture and arts to be Human Rights. Enlarging these ideas and mathematical methods into all fields of culture, ecology, economy, or the like will be the task for the next decades to come.

A comprehensive collection of fundamental principles and applications of analog electronic circuits, including semiconductor diodes, bipolar junction transistors, field-effect transistors (FETs), operational amplifiers, power amplifiers, and feedback circuits. With abundant practical examples, it is an essential reference for researchers, students and engineers in electronical engineering and information processing.

This book presents a contrastive linguistics study of Arabic and English for the dual purposes of improved language teaching and speech processing of Arabic via spectral analysis and neural networks. Contrastive linguistics is a field of linguistics which aims to compare the linguistic systems of two or more languages in order to ease the tasks of teaching, learning, and translation. The main focus of the present study is to treat the Arabic minimal syllable automatically to facilitate automatic speech processing in Arabic. It represents important reading for language learners and for linguists with an interest in Arabic and computational approaches.

If quantum theories of the world are true-and empirical evidence suggests they are-what do they tell us about us, and the world? How should quantum theories make us reevaluate our classical conceptions of material objects? Nearly a century after the development of quantum theories, a consensus has yet to emerge. Many still wonder about what these theories may be telling us about ourselves and our place in the universe. Alyssa Ney here defends and develops a particular framework for understanding the world as it is described by quantum theories. This framework was initially suggested by Schroedinger in the 1920's and was further defended as an account of reality by two philosophers of physics in the 1990's who described it as a necessary point of view for those who argue that quantum theories are correct representations of our world. This framework is called wave function realism, which interprets quantum theories such that its central object is the quantum wave function, interpreted as a field on an extremely high-dimension space. This theory views us, and all objects, as ultimately constituted out of the wave function, and though we seem to occupy three dimensions, the fundamental spatial framework of quantum worlds consists of many more dimensions. Alyssa Ney argues for and advances this view, with the goal of making a case for how this theory how it might be applied to more other relativistic quantum theories, including quantum field theories. Her conclusion develops an account of how we as human beings might ultimately see ourselves and the objects around us as constituted out of the wave function.